Is Your Vit D Supplement Reliable? – JAMA article

Vitamin D is so important to your health, with every cell in your body having a receptor for this key vitamin VDR (Vitamin D receptor), that I’m sure we will continue to discover more ways in which this vitamin promotes health. The fact that our cells have a receptor is a clue to the fact that this of all the vitamins is not a vitamin at all but a hormone. Hormones are produced in one area of the body and have effects at a distant part of the body. From pregnancy, to the newborn, to infants and children, parents and grandparents: if you took only one vitamin/supplement, it should be vitamin D. It also needs to be at much higher doses than the “recommendations”. In pregnancy, take 3-5,000 IU, infants should take 1-1,500 IU, and adolescents and adults should take 5,000 IU. For children, I suspect doses in the middle will be about right. If you get very little sun, then up to 40 lbs (20Kg) should take 2000 IU, 40-80 lbs should take 3000 IU, 80-120 lbs should take 4000 IU, and over 120 lbs can take 5000 IU. If you are obese, you need to take as much as twice the amount I have listed here, especially if you don’t get much sun. This is rather arbitrary as it is difficult to take too much. However, as this is a fat soluble vitamin, it can accumulate and become toxic. How well it is absorbed and the amount per supplement are also variable.

If you live where there is a lot of sun and you are out in the sun a lot you may not need doses this high.

If you have been taking a vitamin D supplement at the upper ranges I list here or way above these amounts, then I suggest you get your vitamin D level checked. I recommend you keep your level between 50-80 ng/ml. Normal is considered 30-100 ng/ml and toxic is over 150 ng/ml.

How do you know you are taking the right brand? Should you buy a particular brand? For many supplements, I do think the brand maters. There are so many cheep vitamins and supplements whose ingredients are from overseas where they are not regulated, so contamination and quality becomes a big issue. This industry is not FDA regulated and quality can vary greatly from company to company. That being said, this is the one supplement that is so important, I would not get hung up on which one to buy. Just get going and take one. The article below from JAMA shows that while there is a good deal of variability, most supplements tested will provide a good amount of vitamin D, and none were so bad that they had way too little or way too much vitamin D.